On a TCP connection, current congestion window size is Congestion Window = 4…
2005
On a TCP connection, current congestion window size is Congestion Window = 4 KB. The window size advertised by the receiver is Advertise Window = 6 KB. The last byte sent by the sender is LastByteSent = 10240 and the last byte acknowledged by the receiver is LastByteAcked = 8192. The current window size at the sender is
- A.
2048 bytes
- B.
4096 bytes
- C.
6144 bytes
- D.
8192 bytes
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Correct answer: B
Compute the sender's usable window by accounting for bytes already in flight and comparing the receiver's available space with the congestion window.
Step 1: Calculate bytes in flight = LastByteSent - LastByteAcked = 10240 - 8192 = 2048 bytes.
Step 2: Receiver's available window = Advertised Window - bytes in flight = 6144 - 2048 = 4096 bytes.
Step 3: Congestion window = 4096 bytes.
Step 4: Sender's usable window = minimum of congestion window and receiver's available window = min(4096, 4096) = 4096 bytes.
Answer: 4096 bytes.
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